A known power storage device includes a stacked electrode assembly formed by stacking a plurality of pairs of electrodes. An example of the power storage device is a lithium ion battery which includes a plurality of positive electrodes, a plurality of negative electrodes, and a plurality of separators and in which the positive electrodes and the negative electrodes are alternately stacked with the separators therebetween. In the case where a so-called stacked electrode structure is used in the lithium ion battery, the stress due to the expansion or contraction of electrodes during charge or discharge is likely to be uniformly generated in an electrode-stacking direction; the strain of an electrode assembly can be reduced as compared to, for example, a wound electrode structure; and the homogenization of a battery reaction, the life extension of a battery, and the like are likely to be achieved.
In the stacked electrode structure, a unit for holding a stacked structure needs to be placed for the purpose of preventing the displacement of an electrode due to vibration. For example, Patent Literature 1 discloses a lithium ion battery in which each of support sheets is placed on a corresponding one of both end surfaces of a stacked electrode assembly in a stacking direction and in which at least two displacement-preventing tapes are attached to each support, sheet so as to be astride the stacked electrode assembly.